The course website and blog for the Fall 2016 instance of Penn State's SC200 course

looking at green

I am always being told that green is good for my eye, so we have to look at green things once in a while to keep our eyes relaxed. But how does it works?

To talk about this question, we will have to talk about colors first. The reason we can see a color is because the reflection of the light. An object will absorb some light between a certain wavelength and reflect the light that can not absorb. Since we know that blue light and the color of light that are related to blue is harmful to our eyes, looking at green can do less harm because the object has already absorbed them. What’s more, if we calculate the reflection into percentage, it will turn out that red reflects 67% of light, yellow reflects 65% while green only reflects 47% of lights. Among all the colors green has the most even reflecting and absorbing rate, so our eyes doesn’t need to work hard to adapt to the color.

Another explanation to this question is where the image formed in our eyes in different colors. The color red focused behind of our retina. That means we have to use our Ciliary muscle to make the image clear. On the other hand, the color green will focus image in front of our retina, so the Ciliary muscle can relax.

Although green is said to be good for our eyes. It doesn’t mean that we can improve our eyesight or won’t get near sighted by just looking at green things. The most important is to really let your eye to rest after working. And looking at something green in a long distance will be a good choice!